The summit main objective is to strengthen the free educational software developers community, with focus on Latin America and the Sugar and olpc communities. The event will feature discussions around future directions and strategy, hacking on specific projects, and exchange of experiences among different deployments.
You can find more information about the summit which ceibalJAM! is organizing on the Sugar Labs wiki and on edujam2011.ceibaljam.org (the second page is only available in Spanish at the moment). Please do note that apart from the date the information on that page is still very preliminary and in constant flux. People are also encouraged to leave their comments and suggestions on this discussion page.
Conozco Uruguay Tour
Additionally a number of extra activities are currently being planned to take place before and after the eduJAM! summit. One of them is the "Conozco Uruguay Tour" which is being organized by members of volunteer organization RAP Ceibal in collaboration with the broader olpc community. It will take place during the days prior to the summit (from Sat April 30 to Thu May 5). For more information please head to the Conozco Uruguay Tour wiki page.
Similarly there's a proposal on the table for a Sugar code sprint immediately following eduJAM! on Sunday May 8th though that hasn't been confirmed yet.
I think it's needless to say that I'm seriously excited about this summit and the accompanying activities. Especially since I had such an excellent time when I visited Uruguay last year during my OLPC News Road Trip and got to meet many of the people who are now making this event happen. Plus it's simply awesome to walk by a random school and see dozens of children using their XOs during the breaks! :-)